Modifying 009 advance curve

[pupjoint]

this is a nice, detailed article by Prof Bruce Smith

http://www.sparkingplugs.com/resources/38-6+$2440+dist+Smith.pdf

suitable for those with 009s lying around and modify them

a few more very interesting write-ups on the tech tips section

[glenn]

The problem is, just changing the springs and lightening the weights only moves the curve up and down the rpm range. it does not change the curve.

The curve on a 009 is linear, pretty much a straight line. The 010 has a cam that the springs rides on and that cam changes the increase in advance as the rpms change.

You can give a 009 the same maximum advance at a specified rpm but the curve is not the same.

Here's the cam on a 019 and 010... the 009 is a totally different design.

[Torben Alstrup]

Well, if you continue to use only one spring there is not that much you can do to the advance curve in the 009. But if you switch to 2 springs you can make it almost as you want. There are so many options with springs that it is impossible to know them all. But take a look down into 3 or 4 different stock distributors. Make a little list of which does what and start playing. It´s not that difficult. With a little legwork you can make the timing curve even better to your engine than a "stock" 019.
T

[glenn]

If the spring tension of 2 springs is the same as one, there will be no change. Mixing and matching springs will move the curve up and down the rpm range but will not change the curve.

If you don't have a distributor tester you really have no idea what the results are. You could do it on an engine with a degree pulley and timing light, but that's not very accurate.

If you want to customize the curve and advance, get the CB Digital and use your laptop to program id.

[pupjoint]

Point taken on the curve. I believe this has also been mentioned in the article in the initial 3rd paragraph. However this is not the objective of modifying it. it is more to make use of the 009s lying around and make it work "better" and serve as a backup.  for what they cost compared to a cast iron, it is a no brainer.

it is interesting to note that the article mentioned

1. the 009 build quality is not as "bad" as perceived in the vw world

2. author explained in detail why the advance for the 009 is not "stable" and accurate.

3. while the author mentioned different advance stop weights, he did not mention anything about changing them, but more like removing the stops and improving sliding surface

this is by far the best and detailed article i have seen written just on this subject . take a look at the 2nd graph versus the first.

[modnrod]

If you don't have a distributor tester you really have no idea what the results are. You could do it on an engine with a degree pulley and timing light, but that's not very accurate.

If you want to customize the curve and advance, get the CB Digital and use your laptop to program id.

I disagree Glenn.
With all due respect to your well-earned reputation, and I mean that as a compliment, if a degree wheel and timing light are not accurate enough then why does everybody use them to get their engine timing "right"?. It's not what you do, but how you do it (carefully and check repeatability is what I mean).
Yes, I have used lots of dizzy testers, and rebuild lots of dizzys, but I can barely find anyone now who even knows what one is!

As much as the CB kit is easy and appears to be a cheap and simple upgrade, playing with weights/springs (and modifying the shape of the weights.........) is part of the fun for us diehard tinkerers.

[pupjoint]

As much as the CB kit is easy and appears to be a cheap and simple upgrade, playing with weights/springs (and modifying the shape of the weights.........) is part of the fun for us diehard tinkerers.

x 2. the Cb digital mentioned by Glenn is not even cheap to begin with. the whole idea is to "improve" the "junk" 009s that we all have lying around somewhere, use them as spares and those are free paperweights.

dont get me wrong, i have been following these 009 german/009 Brazil/010/019/Unilite etc etc debates since the early days when 010 cores were just usd20 and i have 2 of Glenn's rebuilt distributors, but nobody documents these as well as Prof does.

[glenn]

The article was written to modify a 009 to be used in a Porsche 356. The 356 needs a distributor that has 32* built into it and the 009 has only 23*.

The mods only increase the total advance and does not alter the curve. The 009 already has the correct total advance.

As to the quality, i've seen 009s flex at high RPM while the cast iron models are rock stable.

[pupjoint]

The article was written to modify a 009 to be used in a Porsche 356. The 356 needs a distributor that has 32* built into it and the 009 has only 23*.

The mods only increase the total advance and does not alter the curve. The 009 already has the correct total advance.

As to the quality, i've seen 009s flex at high RPM while the cast iron models are rock stable.

yes glenn, it has been mentioned as above many times.

whats the reason for the flexing from your findings? aluminium body?